docs: def plot_lightness(saveplot=False):
      '''Plot lightness of colormaps together.
  
      '''
  
      from colorspacious import cspace_converter
  
      dc = 1.
      x = np.linspace(0.0, 1.0, 256)
      locs = []  # locations for text labels
  
      fig = plt.figure(figsize=(16, 5))
      ax = fig.add_subplot(111)
      fig.subplots_adjust(left=0.03, right=0.97)
      ax.set_xlim(-0.1, len(cm.cmap_d)/2. + 0.1)
      ax.set_ylim(0, 100)
      ax.set_xlabel('Lightness for each colormap', fontsize=14)
  
      for j, cmapname in enumerate(cm.cmapnames):
  
          if '_r' in cmapname:  # skip reversed versions for plot
              continue
  
          cmap = cm.cmap_d[cmapname]  # get the colormap instance
          rgb = cmap(x)[np.newaxis, :, :3]
          lab = cspace_converter("sRGB1", "CAM02-UCS")(rgb)
          L = lab[0, :, 0]
          if L[-1] > L[0]:
              ax.scatter(x+j*dc, L, c=x, cmap=cmap, s=200, linewidths=0.)
          else:
              ax.scatter(x+j*dc, L[::-1], c=x[::-1], cmap=cmap, s=200, linewidths=0.)
          locs.append(x[-1]+j*dc)  # store locations for colormap labels
  
      # Set up labels for colormaps
      ax.xaxis.set_ticks_position('top')
      ticker = mpl.ticker.FixedLocator(locs)
      ax.xaxis.set_major_locator(ticker)
      formatter = mpl.ticker.FixedFormatter([cmapname for cmapname in cm.cmapnames])
      ax.xaxis.set_major_formatter(formatter)
      labels = ax.get_xticklabels()
      for label in labels:
          label.set_rotation(60)
  
      if saveplot:
          fig.savefig('figures/lightness.png', bbox_inches='tight')
          fig.savefig('figures/lightness.pdf', bbox_inches='tight')
  
      plt.show()